An embedded or appliance computing device typically provides a smaller set of features compared to a general-purpose computer. For such devices, it is desired that a more compact operating system, tailored to the defined set of features be used, as opposed to using a general-purpose operating system. Although conventional comprehensive operating systems can be used to drive such embedded/appliance devices, providing the memory and processing power for such operating systems burdens the device manufacturers with expensive overhead that is unnecessary for their product. An ideal solution would be to allow manufacturers of special purpose electronic devices to choose desired features from a comprehensive source operating system to include in a target operating system, and then to build the target operating system that provides only those features that have been chosen. Doing so would allow the device to be smaller and less expensive, thereby making the device more attractive to consumers.
The problem with such a solution, however, is that operating systems are complex programs comprised of a multitude of components. Some components export data or functionality to other components. Some components cannot function properly unless other components are present to provide data or functionality to them. In addition, features of an operating system typically do not map directly to the various components of the operating system. These interdependencies among components of an operating system and the fact that operating system features do not map directly to operating system components provide an obstacle to building a target operating system simply by first selecting features from a source operating system and then building the target operating system from the source operating system based on the selected features. Typically, implementation of a particular feature of an operating system depends on more than one component of the operating system. Furthermore, one component may be required by more than one feature.
Therefore, given a subset of all the features of a source operating system, there is a problem of how to select an appropriate set of operating system components that are necessary to implement the desired feature subset in a target operating system.